Numerical study on heat transfer enhancement of a proton exchange membrane fuel cell with the dimpled cooling channel

As the power density of a proton exchange membrane fuel cell (PEMFC) increases, the problems of internal heat accumulation and non-uniform temperature distribution are becoming significant. In this paper, a novel cooling channel with dimple structures is designed and a three-dimensional PEMFC numerical model is established. When comparing to the conventional channels, the heat transfer performance of dimpled channel is 10% higher than the smooth one, and the pressure loss is almost 13% lower than that of wavy channel. In addition, the optimization of dimple structure parameters is investigated based on the index of uniformity temperature (IUT) and performance evalu-ation criteria (PEC) of heat transfer. It is found that a diameter-to-depth ratio of 4 is rec-ommended when the dimple diameter is less than 0.80 mm. Furthermore, the clock-wise vortex observed inside the dimple is considered to be the main reason affecting heat exchange. This study will contribute to the design of cooling channels for high-power density PEMFCs in the future. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A novel cooling channel with dimple structures is designed and a three-dimensional PEMFC numerical model is established in this paper. Comparing to the conventional channels, the dimpled channel exhibits a 10% higher heat transfer performance and almost 13% lower pressure loss. The optimization of dimple structure parameters based on uniformity temperature index and heat transfer evaluation criteria is carried out, and it is recommended to use a diameter-to-depth ratio of 4 when the dimple diameter is less than 0.80 mm. The clock-wise vortex observed inside the dimple is considered as the main factor affecting heat exchange. This study will contribute to the design of cooling channels for high-power density PEMFCs in the future.